FOLR3: ProductsFolate receptor 3 (FOLR3), also known as folate receptor gamma, is a 32 kDa protein that binds folic acid and reduced folates. Dietary folates are required for many key metabolic processes including nucleotide and methionine synthesis, the interconversion of glycine and serine, and histidine breakdown. Mature FOLR3 is a glycosylated protein that contains an imperfect carboxy terminal GPI anchor sequence. A fraction of FOLR3 is GPI-linked to the cell surface, but the majority is released as a secreted protein. Mature human FOLR3 shares 74% and 83% amino acid (aa) sequence identity with FOLR1 and FOLR2, respectively. Orthologs of human FOLR3 have not been described in mouse or rat. A genetic polymorphism generates a truncated isoform that lacks the carboxy terminal 139 aa. FOLR3 is expressed by cells of the myelocyte and B lymphocyte lineage as well as by various carcinomas. FOLR3 is more highly expressed in ovarian carcinomas than in breast carcinomas or mesotheliomas. Unlike other folate receptors, FOLR3 does not exhibit stereoselectivity in the binding of folates.